3-thia-4-arylquinolin-2-one derivatives

ABSTRACT

This invention describes compounds of Formula (I) which are modulators of potassium channels and are useful for treating conditions affected by abnormal potassium channel activity including erectile dysfunction and irritable bowel syndrome.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Ser. No. 60/511,017 filed Oct. 14, 2003.

BACKGROUND OF THE INVENTION

Potassium channels are transmembrane proteins which are ubiquitously expressed in mammalian cells and represent one of the largest and the most diverse group of ion channels from a molecular perspective. Potassium channels play a key role in regulation of cell membrane potential and modulation of cell excitability. Potassium channels are largely regulated by voltage, cell metabolism, calcium and receptor mediated processes. [Cook, N. S., Trends in Pharmacol. Sciences 1988, 9, 21; and Quast, U., et al., Trends in Pharmacol. Sciences 1989, 10, 431]. Calcium-activated potassium (K_(Ca)) channels are a diverse group of ion channels that share a dependence on intracellular calcium ions for activity. The activity of K_(Ca) channels is regulated by intracellular [Ca²⁺], membrane potential and phosphorylation. On the basis of their single-channel conductances in symmetrical K⁺ solutions, K_(Ca) channels are divided into three subclasses: large conductance (BK or Maxi-K) are those having a conductance of greater than about 150 picosemens (pS); intermediate conductance are those having a conductance of about 50-150 pS; and small conductance are those having a conductance of less than about 50 pS. Large-conductance calcium-activated potassium channels are present in many excitable cells including neurons, cardiac cells and various types of smooth muscle cells. [Singer, J. et al., Pflugers Archiv. 1987, 408, 98; Baro, I., et al., Pflugers Archiv. 1989, 414 (Suppl. 1), S168; and Ahmed, F. et al., Br. J. Pharmacol. 1984, 83, 227].

Potassium ions play a dominant role in controlling the resting membrane potential in most excitable cells and maintain the transmembrane voltage near the K⁺ equilibrium potential (E_(k)) of about −90 milliVolts (mV). It has been shown that opening of potassium channels shift the cell membrane potential towards the E_(k), resulting in hyperpolarization of the cell. [Cook, N. S., Trends in Pharmacol. Sciences 1988, 9, 21]. Hyperpolarized cells show a reduced response to potentially damaging depolarizing stimuli. Those BK channels which are regulated by both voltage and intracellular Ca²⁺ act to limit depolarization and calcium entry and may be particularly effective in blocking damaging stimuli. Therefore cell hyperpolarization via opening of BK channels may result in protection of neuronal cells, as well as other types of cells, e.g., cardiac cells. [Xu, W., Liu, Y., Wang, S., McDonald, T., Van Eyk, J. E., Sidor, A., and O'Rourke, B. Cytoprotective Role of Ca²⁺-activated K⁺ Channels in the Cardiac Inner Mitochondrial Membrane. Science 2002, 298, 1029-1033].

BK channels have been shown to be one of two physiologically relevant potassium channels in relaxing human smooth muscle, including both intestinal and penile smooth muscle. Evidence that relaxation of smooth muscle is beneficial to irritible bowel syndrome and erectile dysfunction has been reported. See the following references: Christ, G. J. Drug News Perspect. 2000, 13, 28-36; Poynard T. et al. Alimentary Pharmacology and Therapeutics 2001, 15, 355-361; and Argentieri, T. M. U.S. Patent Application 2002/0183395.

A variety of synthetic and naturally occurring compounds with BK opening activity have been reported. 4-Aryl-3-hydroxyquinolin-2-one derivatives are disclosed in U.S. Pat. No. 5,892,045, issued Apr. 6, 1999; U.S. Pat. No. 5,922,735, issued Jul. 13, 1999; U.S. Pat. No. 6,353,119, issued Mar. 5, 2002. 4-Arylquinolin-2-one derivatives are disclosed in U.S. Pat. No. 6,184,231, published Feb. 6, 2001 and U.S. Pat. No. 5,972,961, published Oct. 26, 1999. See also Hewawasam, P. et. al. J. Med. Chem. 46 2819-2822 (2003). Other quinolinones are disclosed in U.S. Pat. No. 6,538,022; Japanese Pat. No. 2002371078; and PCT patent application WO 2002026713.

Despite advances in the art, further advances are needed for compounds capable of modulating potassium channels, in particular, large-conductance calcium-activated potassium channels. Such compounds would be useful in treating conditions arising from dysfunction of cellular membrane polarization and conductance.

SUMMARY OF THE INVENTION

This invention describes 3-thia-4-arylquinolin-2-one compounds having the general formula I or pharmaceutically acceptable salts or solvates thereof,

wherein R, R¹, R², R³, R⁴, R⁵, B, and D are as defined below.

The present invention also provides pharmaceutical compositions comprising the atropisomers of 3-thia-4-arylquinolin-2-one derivatives and methods for the treatment of conditions sensitive to potassium channel opening activity such as, for example, ischemia, stroke, convulsions, epilepsy, asthma, irritable bowel syndrome, migraine, traumatic brain injury, spinal cord injury, sexual dysfunction and urinary incontinence.

DETAILED DESCRIPTION OF THE INVENTION

The present invention describes novel 3-thia-4-arylquinolin-2-one compounds and related derivatives of Formula (I) or pharmaceutically acceptable salts or solvates thereof

wherein:

R and R¹ are independently hydrogen or methyl;

R², R³, and R⁴ are independently hydrogen, halogen, cyano, nitro, or trifluoromethyl, provided R², R³, and R⁴ are not all hydrogen;

R⁵ is bromo, chloro, or nitro;

B is —CH₂—, —CH₂CH₂—, —CH═CHCH₂—, —CH₂CH₂CH₂—, or —CH₂CH(OH)CH₂—;

D is OR⁶, CN, N(R⁶)₂, NHC(═O)NHR⁶, or CO₂R⁶;

or B-D taken together is hydrogen;

R⁶ is hydrogen or C₁₋₄ alkyl.

The present invention also provides a method for the treatment or alleviation of disorders associated with BK channels, such as ischemia, stroke, convulsions, epilepsy, asthma, migraine, traumatic brain injury, spinal cord injury, sexual dysfunction, urinary incontinence and especially male erectile dysfunction and irritable bowel syndrome which comprises administering together with a conventional adjuvant, carrier or dilutent a therapeutically effective amount of a compound of formula I or a pharmaceutically acceptable salt thereof.

The term “atropisomer” refers to a stereoisomer resulting from restricted rotation about a single bond where the rotation barrier is high enough to permit isolation of the isomeric species.

The invention encompasses all stereoisomers and tautomers, including atropisomers. Examples of atropisomers and tautomers are shown below.

The terms “racemic mixture” and “racemate” refer to an equimolar or nearly equimolar mixture of two enantiomeric species. In addition, as used herein, the terms “racemic mixture” and “racemate” are intended to include equimolar mixtures of the two atropisomers.

The term “pharmaceutically acceptable salt” is intended to include nontoxic salts synthesized from the parent compound which contains a basic or acidic moiety by conventional chemical methods. Generally, such salts can be prepared by reacting the free acid or base forms of these compounds with a stoichiometric amount of the appropriate base or acid in water or in an organic solvent, or in a mixture of the two; generally, nonaqueous media like ether, ethyl acetate, ethanol, isopropanol, or acetonitrile are preferred. Lists of suitable salts are found in Remington's Pharmaceutical Sciences, 18th ed., Mack Publishing Company, Easton, Pa., 1990, p. 1445. Suitable inorganic bases such as alkali and alkaline earth metal bases include metallic cations such as sodium, potassium, magnesium, calcium and the like. The compounds of the present invention are useful in the form of the free base or acid or in the form of a pharmaceutically acceptable salt thereof. All forms are within the scope of the invention.

The term “halogen” as used herein and in the claims is intended to include fluorine, bromine, chlorine and iodine while the term “halide” is intended to include fluoride, bromide, chloride and iodide anion.

The term “therapeutically effective amount” means the total amount of each active component that is sufficient to show a meaningful patient benefit, i.e., amelioration of acute conditions characterized by openers of large conductance calcium-activated K⁺ channels or increase in the rate of such conditions. When applied to an individual active ingredient, administered alone, the term refers to that ingredient alone. When applied to a combination, the term refers to combined amounts of the active ingredients that result in the therapeutic effect, whether administered in combination, serially or simultaneously.

The term “compounds of the invention”, and equivalent expressions, are meant to embrace compounds of Formula I and include prodrugs, pharmaceutically acceptable salts, and solvates, e.g. hydrates. Similarly, reference to intermediates, whether or not they themselves are claimed, is meant to embrace their salts, and solvates, where the context so permits.

The term “derivative” means a chemically modified compound wherein the modification is considered routine by the ordinary skilled chemist, such as an ester or an amide of an acid, protecting groups, such as a benzyl group for an alcohol or thiol, and tert-butoxycarbonyl group for an amine.

The term “solvate” means a physical association of a compound of this invention with one or more solvent molecules. This physical association includes hydrogen bonding. In certain instances the solvate will be capable of isolation, for example when one or more solvent molecules are incorporated in the crystal lattice of the crystalline solid. “Solvate” encompasses both solution-phase and isolable solvates. Exemplary solvates include hydrates, ethanolates, methanolates, and the like.

The term “patient” includes both human and other mammals.

The term “pharmaceutical composition” means a composition comprising a compound of the invention in combination with at least one additional pharmaceutical carrier, i.e., adjuvant, excipient or vehicle, such as diluents, preserving agents, fillers, flow regulating agents, disintegrating agents, wetting agents, emulsifying agents, suspending agents, sweetening agents, flavoring agents, perfuming agents, antibacterial agents, antifungal agents, lubricating agents and dispensing agents, depending on the nature of the mode of administration and dosage forms. Ingredients listed in Remington's Pharmaceutical Sciences, 18^(th) ed., Mack Publishing Company, Easton, Pa. (1999) for example, may be used.

The phrase “pharmaceutically acceptable” is employed herein to refer to those compounds, materials, compositions, and/or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the-tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication commensurate with a reasonable risk/benefit ratio.

The term “pharmaceutically acceptable prodrugs” as used herein means those prodrugs of the compounds useful according to the present invention which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of humans and lower animals without undue toxicity, irritation, allergic response, and the like, commensurate with a reasonable risk/benefit ratio, and effective for their intended use, as well as zwitterionic forms, where possible, of the compounds of the invention.

The term “prodrugs”, as the term is used herein, are intended to include any covalently bonded carriers which release an active parent drug of the present invention in vivo when such prodrug is administered to a patient. Since prodrugs are known to enhance numerous desirable qualities of pharmaceuticals (i.e., solubility, bioavailability, manufacturing, etc.) the compounds of the present invention may be delivered in prodrug form. Thus, the skilled artisan will appreciate that the present invention encompasses prodrugs of the presently claimed compounds, methods of delivering the same, and compositions containing the same. Prodrugs of the present invention are prepared by modifying functional groups present in the compound in such a way that the modifications are cleaved, either in routine manipulation or in vivo, to form the parent compound. The transformation in vivo may be, for example, as the result of some metabolic process, such as chemical or enzymatic hydrolysis of a carboxylic, phosphoric or sulphate ester, or reduction or oxidation of a susceptible functionality. Prodrugs include compounds of the present invention wherein a hydroxy, amino, or sulfhydryl group is bonded to any group that, when the prodrug of the present invention is administered to a patient, it cleaves to form a free hydroxyl, free amino, or free sulfydryl group, respectively. Functional groups which may be rapidly transformed, by metabolic cleavage, in vivo form a class of groups reactive with the carboxyl group of the compounds of this invention. They include, but are not limited to such groups as alkanoyl (such as acetyl, propionyl, butyryl, and the like), unsubstituted and substituted aroyl (such as benzoyl and substituted benzoyl), alkoxycarbonyl (such as ethoxycarbonyl), trialkylsilyl (such as trimethyl- and triethysilyl), monoesters formed with dicarboxylic acids (such as succinyl), and the like. Because of the ease with which the metabolically cleavable groups of the compounds useful according to this invention are cleaved in vivo, the compounds bearing such groups can act as prodrugs. The compounds bearing the metabolically cleavable groups have the advantage that they may exhibit improved bioavailability as a result of enhanced solubility and/or rate of absorption conferred upon the parent compound by virtue of the presence of the metabolically cleavable group. A thorough discussion of prodrugs is provided in the following: Design of Prodrugs, H. Bundgaard, ed., Elsevier, 1985; Methods in Enzymology, K. Widder et al, Ed., Academic Press, 42, p.309-396, 1985; A Textbook of Drug Design and Development, Krogsgaard-Larsen and H. Bundgaard, ed., Chapter 5; “Design and Applications of Prodrugs” p.113-191, 1991; Advanced Drug Delivery Reviews, H. Bundgard, 8, p.1-38, 1992; Journal of Pharmaceutical Sciences, 77, p. 285, 1988; Chem. Pharm. Bull., N. Nakeya et al, 32, p. 692, 1984; Pro-drugs as Novel Delivery Systems, T. Higuchi and V. Stella, Vol. 14 of the A.C.S. Symposium Series, and Bioreversible Carriers in Drug Design, Edward B. Roche, ed., American Pharmaceutical Association and Pergamon Press, 1987.

One aspect of the invention are compounds of Formula I where R is hydrogen.

Another aspect of the invention are compounds of form Formula I where R¹ is hydrogen.

Another aspect of the invention are compounds of Formula I where R² is hydrogen, R³ is trifluoromethyl, and R⁴ is hydrogen.

Another aspect of the invention are compounds of Formula I where R⁵ is chloro.

Another aspect of the invention are compounds of formula I where B-D is hydrogen.

Some compounds of the invention include

[4-(5-Chloro-2-hydroxy-phenyl)-2-oxo-6-trifluoromethyl- 1 ,2-dihydro-quinolin-3-ylsulfanyl]-acetic acid;

1-{2- [4-(5-Chloro-2-methoxy-phenyl)-2-oxo-6-trifluoromethyl- 1,2-dihydro-quinolin-3-ylsulfanyl]-ethyl}-3-methyl-urea;

1-{2- [4-(5-Chloro-2-methoxy-phenyl)-2-oxo-6-trifluoromethyl- 1,2-dihydro-quinolin-3-ylsulfanyl]-ethyl}-3-ethyl-urea;

1-{2- [4-(5-Chloro-2-methoxy-phenyl)-2-oxo-6-trifluoromethyl- 1,2-dihydro-quinolin-3-ylsulfanyl]-ethyl}urea;

1-{2-[4-(5-Chloro-2-hydroxy-phenyl)-2-oxo-6-trifluoromethyl- 1,2-dihydro-quinolin-3-ylsulfanyl]-ethyl}urea;

1-{2- [4-(5-Chloro-2-hydroxy-phenyl)-2-oxo-6-trifluoromethyl- 1,2-dihydro-quinolin-3-ylsulfanyl]-ethyl}-3-methyl-urea;

1-{2-[4-(5-Chloro-2-hydroxy-phenyl)-2-oxo-6-trifluoromethyl-1,2-dihydro-quinolin-3-ylsulfanyl]-ethyl}-3-ethyl-urea;

4-(5-Chloro-2-hydroxyphenyl)-3-mercapto-6-trifluoromethyl- 1 H-quinolin-2-one;

4-(5-Chloro-2-methoxyphenyl)-3-mercapto-6-trifluoromethyl- 1 H-quinolin-2-one;

4-(5 -Chloro-2-hydroxyphenyl)-3-(2-hydroxyethylsulfanyl)-6-trifluoromethyl-H-quinolin-2-one;

3-[4-(5-Chloro-2-hydroxyphenyl)-2-oxo-6-trifluoromethyl- 1,2-dihydro-quinolin-3-ylsulfanyl]propionitrile;

4-(5-Chloro-2-hydroxyphenyl)-3-(2-methoxyethylsulfanyl)-6-trifluoromethyl- 1 H-quinolin-2-one;

4-[4-(5-Chloro-2-hydroxyphenyl)-2-oxo-6-trifluoromethyl- 1,2-dihydro-quinolin-3-ylsulfanyl]butyronitrile;

4- (5-Chloro-2-hydroxyphenyl)-3-(3-hydroxypropylsulfanyl)-6-trifluoromethyl-H-quinolin-2-one;

4-(5-Chloro-2-methoxyphenyl)-3-(3-hydroxypropylsulfanyl)-6-trifluoromethyl-1H-quinolin-2-one;

4-(5-Chloro-2-methoxyphenyl)-3-(2-hydroxyethylsulfanyl)-6-trifluoromethyl- H-quinolin-2-one;

(±)-4-(5-Chloro-2-hydroxyphenyl)-3-(2,3-dihydroxypropylsulfanyl)-6-trifluoromethyl-1H-quinolin-2-one;

(S)-4-(5-Chloro-2-hydroxyphenyl)-3-(2,3-dihydroxypropylsulfanyl)-6-trifluoromethyl- 1 H-quinolin-2-one;

(R)-4-(5-Chloro-2-hydroxyphenyl)-3-(2,3-dihydroxypropylsulfanyl)-6-trifluoromethyl- 1 H-quinolin-2-one;

4-(5-Chloro-2-methoxyphenyl)-3-(2,3-dihydroxypropylsulfanyl)-6-trifluoromethyl-1H-quinolin-2-one; and

4-(5-Chloro-2-methoxy-phenyl)-3-(3 -hydroxy-propenylsulfanyl)-6-trifluoromethyl-4a,8a-dihydro-1H-quinolin-2-one;

and salts and solvates thereof.

Certain of the compounds of the present invention can exist in unsolvated forms as well as solvated forms including hydrated forms such as monohydrate, dihydrate, hemihydrate, trihydrate, tetrahydrate and the like. The products may be true solvates, while in other cases, the products may merely retain adventitious solvent or be a mixture of solvate plus some adventitious solvent. It should be appreciated by those skilled in the art that solvated forms are equivalent to unsolvated forms and are intended to be encompassed within the scope of the present invention.

Synthetic Methods

The compounds of Formula I may be prepared by various procedures such as those illustrated herein in the examples and in the Reaction Schemes described in the specific embodiments and variations thereof which would be evident to those skilled in the art.

The following reaction schemes illustrate representative general procedures for the preparation of intermediates and methods for the preparation of compounds of Formula I according to this invention. It should also be evident to those skilled in the art that appropriate substitution of both the materials and methods disclosed herein will produce the examples illustrated below and those encompassed by the scope of this invention.

Reagents and conditions: (a) bromoacetyl bromide, pyridine, CH₂Cl₂, 0° C.; (w) (i. BBr₃, CH₂Cl₂), ii. NaH, methyl thioglycolate, III, r.t.; (x) 10 N NaOH, THF.

Reagents and conditions: (e) HS(CH₂) ₂NHBoc, NaH, THF; (f) HCl, EtOH; (g) Isocyanate; (h) BBr₃, CH₂Cl₂.

Reagents and conditions: (p) tBuSH, NaH, THF; (q) BBr₃, CH₂Cl₂; (r) TFA; (s) NaH, HS-B-D.

Reagents and conditions: (t) epibromohydrin, NaOH, EtOH; (u) LDA, THF.

Biological Methods

Openers of BK channels exert their cellular effects by increasing the open probability of these channels [Gribkoff, V. K., et al., Neuroscientist, 7:166-177 (2001); Gribkoff, V. K. et al., Adv. Pharmacol., 37:319-348 (1997); McKay, M. C., et al., J. Neurophysiol., 71: 1873-1882 (1994); and Olesen, S. -P., Exp. Opin. Invest. Drugs, 3: 1181-1188 (1994)]. This increase in the opening of individual BK channels collectively results in the hyperpolarization of cell membranes, particularly in depolarized cells, produced by significant increases in whole-cell BK-mediated conductance. Hyperpolarization, in turn, reduces the excitability of nerve and muscle cells, and decreases the open probability of voltage-dependent Ca²⁺ channels, effectively lowering intracellular concentrations of this potentially harmful cation. The effect on smooth muscle is that of relaxation.

Assay for BK Channel Openers

The ability of the compounds of the invention to open BK channels and increase whole-cell outward (K⁺) BK-mediated currents was assessed under voltage-clamp conditions by determining their ability to increase cloned mammalian (mSlo or hSlo) BK-mediated outward current heterologously expressed in Xenopus oocytes [Butler, A., et al., Science 1993, 261, 221-224; Dworetzky, S. I., et al., Mol. Brain Res. 1994, 27, 189-193; Gribkoff, V. K., et al., Mol. Pharmacol. 1996, 50, 206-217]. The two BK constructs employed represent nearly structurally identical homologous proteins, and have proven to be pharmacologically indistinguishable in our tests. To isolate BK current from native (background, non-BK) current, the specific and potent BK channel-blocking toxin iberiotoxin (IBTX) [Galvez, A., et al., J. Biol. Chem. 1990, 265, 11083-11090] was employed at a supramaximal concentration, e.g., 50-100 nanomolar (“nM”). The relative contribution of BK channel-mediated current to total outward current was determined by subtraction of the current remaining in the presence of IBTX (non-BK current) from the current profiles obtained in all other experimental conditions (control, drug, and wash) [Gribkoff, V. K. et al., Mol. Pharmacol. 1996, 50, 206-217]. It was determined that at the tested concentrations the compounds profiled did not significantly effect non-BK native currents in the oocytes. All compounds were tested in 5-10 oocytes and are reported at the indicated concentration of 20 micromolar (“μM”) (or as otherwise indicated); the effect of the selected compounds of the invention on BK current was expressed as the percent of control IBTX-sensitive current at a single transmembrane voltage (+140 mV) and is listed in Table 1. Recordings were accomplished using standard two-electrode voltage clamp techniques [Stuhmer, W., et al., Methods in Enzymology, 1992, 207, 319-339]; voltage-clamp protocols consisted of 500-750 milliseconds (“ms”) duration step depolarizations, from a holding potential of −60 mV, to a final voltage up to +140 mV in 20 mV steps. The experimental media (modified Barth's solution) consisted of millimolar (“mM”): NaCl (88), NaHCO₃ (2.4), KCl (1.0), HEPES (10), MgSO₄ (0.82), Ca(NO₃)₂ (0.33), CaCl₂ (0.41); pH 7.5.

Rat Small Intestine

The ability of the compounds of the invention to relax rat small intestine tissue as a model for the treatment of irritable bowel syndrome is described as follows. Male rats (Harlan, Sprague Dawley, 250-350 g) were sacrificed by decapitation. A portion of small intestine (ileum) was removed and the attached connective tissues and intestinal contents removed. The ileum was cut into segments of ≦1 cm in length. The segments were mounted longitudinally between fixed hooks in organ baths containing warm (37° C.) physiological salt solution (composition in mM: NaCl 118.4, KCl 4.7, KH₂PO4 1.2, MgSO₄ 1.2, CaCl₂ 1.8, Glucose 10.1, NaHCO₃ 25; gassed with 95% O₂/ 5% CO₂, pH 7.4). A stable tension of ˜1.5 g was maintained in the tissue segments during the equilibration period of 45 minutes. Changes in muscle tension were measured with isometric force transducers (Grass, FT-03C) and recorded using AcqKnowledge data acquisition system (AcqKnowledge for MP100WS, Biopac Systems Inc., Goleta, Calif.). Compound or vehicle was added in the baths for 30 minutes. “Zero” active force was established at the end of the experiment using nifedipine (20 μM). The effects of compounds or vehicle on force was determined by measuring the integral of nifedipine-sensitive force (including resting tone and spontaneous contractions) pre- and 30 min post-compound (or vehicle) addition. Results are expressed as the percentage inhibition of force. DMSO vehicle inhibited force (integral) by −0.6±3.0% (n=25). Results are summarized in Table 1.

Rabbit Corpus Cavernosum

The ability of the compounds of the invention to relax rabbit corpus cavernosum tissue as a model for the treatment of erectile dysfunction is described as follows. New Zealand white rabbits (3.4-3.7 kg) were euthanized by sodium pentobarbital (100 mg/kg) overdose. The penis from each animal was rapidly removed and immersed in a cold oxygenated modified Krebs Henseleit bicarbonate buffer. The penis' outer tunica was removed and the corpus cavernosum smooth muscle obtained and cut into strips approximately 3-5 mm long. The strips were suspended in tissue baths containing physiological salt solution (see above), and allowed to equilibrate for at least one hour under resting tension of 1.0 gram. Isometric force was measured as described above. Tissue strips were stimulated with the α-agonist phenylephrine (3 μM) and allowed to reach a steady level of force prior to the addition of test compounds. The results are expressed as the percentage inhibition of phenylephrine-induced force as compared to vehicle control. Results are summarized in Table 1. TABLE 1 % % Inhibition Inhibition of force of force % MaxiK (RCC (RSI Example Structure opening* strips) strips) 1

155 14 3

123 17b 4

140 5

165 65 21 6

176 7

  160^(⋄⋄) 8

197 9

  149^(⋄) 10

348 43 11

189 12

  208^(⋄) 13

198 14

242 23 15

140 16

149 17

246 31 6 18

223 45 19

256 41 20

178 21

  135^(⋄) *at 20 μM (unless otherwise indicated) expressed as percent increase over BK current in controls, voltage step to +140 mV ^(⋄)at 1 μM.

The results of the above biological tests demonstrate that the compounds of the invention are potent openers of large-conductance calcium-activated K⁺ channels (BK or Maxi-K channels) and are effective at relaxing intestinal and penile smooth muscle.

Pharmaceutical Compositions and Methods of Use

The compounds of the present invention are useful for the treatment of patients for conditions arising from dysfunction of cellular membrane polarization and conductance and are indicated for the treatment of ischemia, stroke, convulsions, epilepsy, asthma, migraine, traumatic brain injury, spinal cord injury, sexual dysfunction, urinary incontinence and especially male erectile dysfunction and irritable bowel syndrome, as well as other disorders sensitive to BK channel activity. Accordingly, in one aspect of the present invention, there is provided a method of treatment or prevention of conditions responsive to opening of potassium channels in a patient in need thereof, which comprises administering to the patient a therapeutically effective amount of a compound of Formula I or a pharmaceutically acceptable salt, solvate or prodrug thereof. In another aspect, this invention provides a method for the treatment of or protection from disorders which are mediated by opening of the large conductance calcium-activated K⁺ channels in a patient in need thereof, which comprises administering to the patient a therapeutically effective amount of a compound of Formula I or a pharmaceutically acceptable salt, solvate or prodrug thereof. Preferably, the compounds of Formula I are useful in the treatment of ischemia, stroke, convulsions, asthma, irritable bowel syndrome, migraine, traumatic brain injury, urinary incontinence, irritable bowel syndrome, and sexual dysfunction in both men (erectile dysfunction, for example, due to diabetes mellitus, spinal cord injury, radical prostatectomy, psychogenic etiology or any other cause) and women by improving blood flow to the genitalia, especially the corpus cavernosum, and other disorders sensitive to BK channel activating activity.

In another aspect, this invention provides pharmaceutical compositions comprising at least one compound of Formula I and a carrier.

The pharmaceutical compositions include suitable dosage forms for oral, parenteral (including subcutaneous, intramuscular, intradermal and intravenous) bronchial or nasal administration. Thus, if a solid carrier is used, the preparation may be tableted, placed in a hard gelatin capsule in powder or pellet form, or in the form of a troche or lozenge. The solid carrier may contain conventional excipients such as binding agents, fillers, tableting lubricants, disintegrants, wetting agents and the like. The tablet may, if desired, be film coated by conventional techniques. If a liquid carrier is employed, the preparation may be in the form of a syrup, emulsion, soft gelatin capsule, sterile vehicle for injection, an aqueous or non-aqueous liquid suspension, or may be a dry product for reconstitution with water or other suitable vehicle before use. Liquid preparations may contain conventional additives such as suspending agents, emulsifying agents, wetting agents, non-aqueous vehicle (including edible oils), preservatives, as well as flavoring and/or coloring agents. For parenteral administration, a vehicle normally will comprise sterile water, at least in large part, although saline solutions, glucose solutions and like may be utilized. Injectable suspensions also may be used, in which case conventional suspending agents may be employed. Conventional preservatives, buffering agents and the like also may be added to the parenteral dosage forms. Particularly useful is the administration of a compound of Formula I directly in parenteral formulations. The pharmaceutical compositions are prepared by conventional techniques appropriate to the desired preparation containing appropriate amounts of the active ingredient, that is, the compound of Formula I according to the invention.

The dosage of the compounds of Formula I to achieve a therapeutic effect will depend not only on such factors as the age, weight and sex of the patient and mode of administration, but also on the degree of potassium channel activating activity desired and the potency of the particular compound being utilized for the particular disorder of disease concerned. It is also contemplated that the treatment and dosage of the particular compound may be administered in unit dosage form and that the unit dosage form would be adjusted accordingly by one skilled in the art to reflect the relative level of activity. The decision as to the particular dosage to be employed (and the number of times to be administered per day) is within the discretion of the physician, and may be varied by titration of the dosage to the particular circumstances of this invention to produce the desired therapeutic effect.

A suitable dose of a compound of Formula I or pharmaceutical composition thereof for a mammal, including man, suffering from, or likely to suffer from any condition as described herein is an amount of active ingredient from about 0.01 micrograms per kilogram (μg/kg) to 50 milligrams per kilogram (mg/kg) body weight and preferrably, from about 0.1 μg/kg to 5 mg/kg body weight for oral administration. For parenteral administration, the dose may be in the range of 0.1 μg/kg to 1 mg/kg body weight for intravenous administration. The active ingredient will preferably be administered in equal doses from one to four times a day. However, usually a small dosage is administered, and the dosage is gradually increased until the optimal dosage for the host under treatment is determined.

The compounds of the present invention may be employed alone or in combination with other suitable therapeutic agents useful in the treatment of the dysfunction of cellular membrane polarization and conductance, e.g., sexual dysfunction such as cyclic guamine monophosphate, phosphodiaterase (cGMP PDE) inhibitors and particularly cGMP PDE V inhibitors such as sildenafil. Exemplary of the therapeutic agents are PDE V inhibitors selected from imidazo-quinazolines (see WO 98/08848), carbazoles (see WO 97/03675, WO 97/03985 and WO 95/19978), imidazopurinones (see WO 97/19947), benzimidazoles (see WO 97/24334), pyrazoloquinolines (see U.S. Pat. No. 5,488,055), anthranilic acid derivatives (see WO 95/18097), fused heterocycles (see WO 98/07430) and thienopyrimidines (see DE 19632423). Alosetron hydrochloride can be combined with the compounds of the present invention to treat irritable bowel syndrome (see, e.g., U.S. Pat. Nos. 5,360,800 and 6,284,770).

The amount of compound actually administered will be determined by a physician using sound medical judgement.

DESCRIPTION OF SPECIFIC EMBODIMENTS

The following examples are given by way of illustration and are not to be construed as limiting the scope of the claims which follow.

In the following examples, all temperatures are given in degrees Centigrade. Melting points were recorded on a Gallenkamp capillary melting point apparatus are uncorrected. Proton magnetic resonance (¹H NMR) spectra were recorded on a Bruker AC 300 or 500 megaHertz (“MHz”) spectrometer. All spectra were determined in the solvents indicated and chemical shifts are reported in δ units downfield from the internal standard tetramethylsilane (TMS) and interproton coupling constants are reported in Hertz (Hz). Splitting patterns are designated as follows: s, singlet; d, doublet; t, triplet; q, quartet; m, multiplet; br, broad peak; dd, doublet of doublet; bd, broad doublet; dt, doublet of triplet; bs, broad singlet; dq, doublet of quartet. Infrared (IR) spectra using potassium bromide (KBr) were determined on a Perkin Elmer 781 spectrometer from 4000 cm⁻¹ to 400 cm⁻¹, calibrated to 1601 cm⁻¹ absorption of a polystyrene film and reported in reciprocal centimeters (cm⁻¹). Low resolution mass spectra (MS) and the apparent molecular weight (MH⁺) or (M-H)⁻ was determined on a Finnigan TSQ 7000. LC-MS analysis were carried out on a Shimadzu instrument using one of the following methods (1) YMC ODS C18 column (4.6×33 mm) employing a 4 min linear gradient of 0% to 100% solvent B in A and a 1 min hold at 100% B (2) YMC ODS C18 column (4.6×30 mm) employing a 2 min linear gradient of 0% to 100% solvent B in A and a 1 min hold at 100% B (3) YMC ODS C18 column (3.0×50 mm) employing a 2 min linear gradient of 0% to 100% solvent B in A and a 1 min hold at 100% B (4) YMC ODS C18 column (3.0×50 mm) employing a 4 min linear gradient of 0% to 100% solvent B in A and a 1 min hold at 100% B. In all cases solvent A: 10% methanol, 90% water, 0.1% TFA; and solvent B: 90% methanol, 10% water, 0.1% TFA with UV detector set at 220 nm. The element analyses are reported as percent by weight. Unless otherwise indicated in the Specific Embodiments, R² and R⁴ are H in the descriptive title of the Examples.

Intermediate 1

2-Bromo-N-[2-(5-chloro-2-methoxy-benzoyl)-4-trifluoromethyl-phenyl]-acetamide. To a solution of (2-Amino-5-trifluoromethyl-phenyl)-(5-chloro-2-methoxy-phenyl)-methanone (IV)(14.13 g, 42.9 mmol, 1 eq) in Dichloromethane (120 mL) at 0° C. was added pyridine (4.65 mL, 57.5 mmol, 1.34 eq), then Bromoacetyl bromide (4.98 mL, 57.2 mmol, 1.33 eq). After 3 h, the reaction was quenched with Sodium bicarbonate (aq) and extracted three times into Dichloromethane. The combined organic layers were dried over Magnesium sulfate, filtered and concentrated in vacuo. The product was used without further purification. ¹H NMR (300 MHz, CDCl3) δ 12.18 (s, 1H), 8.88 (d, J=8.9 Hz, 1H), 7.82 (dd, J=1.9, 8.9 Hz, 1H), 7.71 (d, J=1.9 Hz, 1H), 7.51 (dd, J=2.6, 8.9 Hz, 1H), 7.41 (d, J=2.6 Hz, 1H), 6.97 (d, J=8.9 Hz, 1H), 4.08 (s, 2H), 3.70 (s, 3H).

Intermediate 2

[4-(5-Chloro-2-hydroxy-phenyl)-2-oxo-6-trifluoromethyl-1,2-dihydro-quinolin-3-ylsulfanyl]-acetic acid methyl ester. To make the phenolic series (R═H), first follow the following procedure: To a solution of V (16.3 mmol, 1 eq) in Dichloromethane (56 mL) at −78° C. was added a 1 M solution of Boron tribromide in Dichloromethane (25 mL, 25 mmol, 1.5 eq). After the addition was complete, the reaction was brought to RT, and stirred for an additional 2 h. The reaction was brought back to −78° C., and quenched with Sodium bicarbonate (sat'd). The mixture was extracted into Dichloromethane, dried over Magnesium sulfate, and dried in vacuo.

To a stirred suspension of Sodium hydride (838 mg of a 60% dispersion in mineral oil, 20.9 mmol, 2 eq) in THF (150 mL) was added methyl thioglycolate (1.86 mL, 20.9 mmol, 2 eq) and allowed to stir at RT for 10 minutes. A solution of V (4.57 g, 10.5 mmol, 1 eq) in THF was then added, and the mixture stirred for 3 h. More Sodium hydride (418 mg, 10.5 mmol, leq) was added, and stirring continued overnight. The reaction was carefully quenched with 1N HCl, and extracted three times into EtOAc. The combined organic layers were dried over Magnesium sulfate, and concentrated in vacuo.

¹H NMR (300 MHz, CDCl3) δ 12.64 (s, 1H), 8.06 (d, J=8.9 Hz, 2H), 7.68 (d, J=7.1 Hz, 1H), 7.47 (dd, J=2.6, 8.9 Hz, 1H), 7.38-7.31 (m, 4H), 7.12 (d, J=2.6 Hz, 1H), 6.97 (d, J=8.9 Hz, 1H), 3.64 (s, 3H).

Example 1

[4-(5-Chloro-2-hydroxy-phenyl)-2-oxo-6-trifluoromethyl-1,2-dihydro-quinolin-3-ylsulfanyl]-acetic acid. The crude compound IIa was taken up in THF to which 1ON NaOH was added (1:1 by volume). After stirring overnight, the reaction was quenched with 4N HCl, and extracted three times to EtOAc. The combined organic layers were dried over Magnesium sulfate, and concentrated in vacuo. The product was taken up in warm 95% Dichloromethane/MeOH. After cooling, the white solid was filtered off and dried to give pure Ia. ¹H NMR (300 MHz, CDCl₃) 3.52 (d, J=15 Hz, 1H), 3.68 (s, 3H), 6.98 (d, J=8.9 Hz, 1H), 7.06(d, J=2.6 Hz, 1H), 7.27(s, 1H), 7.44-7.45 (m, 2H), 7.66 (d, J=8.7 Hz, 1H); mp=235° C.; LC/MS m/e 444 (MH⁺).

Intermediate 3

{2-[4-(5-Chloro-2-methoxy-phenyl)-2-oxo-6-trifluoromethyl-1,2-dihydro-quinolin-3-ylsulfanyl]-ethyl}-carbamic acid tert-butyl ester. To a solution of t-butyl N-(2mercaptoethyl) carbamate (2.17 ml, 9.78 mmol) in THF at 0° C., NaH (400 mg, 9.8 mmol) was added. The mixture was allowed to stir under N₂. After 10 min. III (2.2 g, 4.89 mmol) was added and allowed to warm to rt over 2.5 hr. The reaction was acidified with 1 N HCl and basified with 4 N NaOH followed by extraction with EtOAc, dried over MgSO₄, and evaporated to give V. ¹H NMR (300 MHz, CDCl₃) 1.46 (s, 9H), 3.23-3.35 (m, 4H), 3.75 (s, 3H), 7.06(d, J=8.9 Hz, 1H), 7.12(d, J=2.5 Hz, 1H), 7.28 (s, 1H), 7.51 (d, J=8.9, 2.6 Hz, 1H), 7.56 (d, J=8.5 Hz, 1H) 7.73 (d, J=8.7 Hz, 1H) LC/MS m/e 529 (MH)⁺.

Intermediate 4

3-(2-Amino-ethylsulfanyl)-4-(5-chloro-2-methoxy-phenyl)-6-trifluoromethyl-1H-quinolin-2-one. A solution of V (220 mg) was heated to reflux with 3 N HCl (4 ml) in EtOH (4 ml) for 2 hr. After cooling to rt, the solution was basified with 10 N NaOH followed by Et₂O extraction, brine wash, and evaporated to give a yellow solid VI. mp=>260° C.; ¹H NMR (300 MHz, CDCl₃) 2.77 (t, J=6.1 Hz, 2H), 3.09-3.22 (m, 2H), 3.75 (s, 3H), 7.04 (d, J=8.9 Hz, 1H), 7.12 (d, J=2.5 Hz, 1H), 7.30 (s, 1H), 7.49 (d, J=8.9, 2.6 Hz, 1H), 7.60 (d, J=8.6 Hz, 1H), 7.72 (d, J=8.6 Hz, 1H).

Procedure to Prepare Examples 2, 3 and 4

A solution of VI (100 mg 0.23 mmol) in DCM was cooled to 0° C. followed by addition of Methyl isocyanate under N₂. The mixture was allowed to stir for 20 min followed by evaporation to give a white solid Example 2. Ethyl isocyanate was used to form Example 3; Example 4 was formed using Sodium isocyanate in acetic acid (1 eq)/water.

EXAMPLE 2

1-{2-[4-(5-Chloro-2-methoxy-phenyl)-2-oxo-6-trifluoromethyl-1,2-dihydro-quinolin-3-ylsulfanyl]-ethyl}-3-methyl-urea. ¹H NMR (300 MHz, CDCl₃) 2.79-3.36 (m, 4H), 3.71 (s, 3H), 7.02 (d, J=8.9 Hz, 1H), 7.08 (d, J=2.5 Hz, 1H), 7.23 (s, 1H), 7.41 (d, J=8.9 Hz, 1H), 7.47 (d, J=8.9, 2.6 Hz, 1H), 7.66 (d, J=8.9 Hz, 1H) LC/MS m/e 472 (MH)⁺; C₂₀H₁₇ClF₃N₃O₃S.0.2H₂O; EA calc'd C=50.52, H=3.69, S=6.74, F=11.99, found C=50.58, H=3.93, S=6.39, F=11.94; mp=187-190° C.

EXAMPLE 3

1-{2-[4-(5-Chloro-2-methoxy-phenyl)-2-oxo-6-trifluoromethyl-1,2-dihydro-quinolin-3-ylsulfanyl]-ethyl}-3-ethyl-urea. ¹H NMR (300 MHz, CDCl₃) 2.43 (s, 3H), 2.86-2.94 (m, 2H), 3.10-3.18 (m, 2H), 3.60-3.63 (m, 2H), 3.78 (s, 3H), 7.08 (d, J=8.9 Hz, 1H), 7.12 (d, J=2.6 Hz, 1H), 7.24 (s, 1H), 7.52 (d, J=8.9, 2.6 Hz, 1H), 7.59 (d, J=8.6 Hz, 1H), 7.68 (d, J=8.6 Hz, 1H), LC/MS m/e 486 (MH)⁺; C₂₁H₁₉ClF₃N₃O₃S. 0.7H₂O EA calc'd N=8.43, H=4.12, S=6.43, F=11.43, found N=8.01, H=3.88, S=6.51, F=10.79; mp=209-211° C.

EXAMPLE 4

1-{2-[4-(5-Chloro-2-methoxy-phenyl)-2-oxo-6-trifluoromethyl-1,2-dihydro-quinolin-3-ylsulfanyl]-ethyl}urea. ¹H NMR (300 MHz, DMSO) 0.92 (t, J=7.1 Hz, 3H), 2.88-2.99 (m, 6H), 3.68 (s, 3H), 5.77-5.81 (m, 2H), 7.03 (s, 1H), 7.25 (d, J=8.9 Hz, 1H), 7.30 (d, J=2.6 Hz, 1H), 7.56 (d, J=8.7 Hz, 1H), 7.57 (d, J=8.8 Hz, 1H), 7.82 (d, J=8.7 Hz, 1H), 12.44 (s, 1H), LC/MS m/e 500 (MH)⁺; C₂₂H₂₁ClF₃N₃O₃S. 0.3H₂O EA calc'd C=52.29, N=8.32, H=4.31, S=6.34, found C=52.13, H=4.20, N=8.32, S=6.34; mp=228-230° C.

Procedure to Prepare Examples 5, 6 and 7

A solution of BBr₃, 1M in DCM (15.5 ml) was added to a cold (−78° C.) solution of Ib (4.7 g) which was then allowed to warm to rt. After 1.5 hr the mixture was cooled back to −78° C. and was quenched with sat. NaHCO₃, warmed back to rt., extracted to EtOAc, dried over MgSO₄, and evaporated to give Ic.

EXAMPLE 5

1-{2-[4-(5-Chloro-2-hydroxy-phenyl)-2-oxo-6-trifluoromethyl-1,2-dihydro-quinolin-3-ylsulfanyl]-ethyl}urea. LC/MS m/z 457 (MH)⁺.

EXAMPLE 6

1-{2-[4-(5-Chloro-2-hydroxy-phenyl)-2-oxo-6-trifluoromethyl-1,2-dihydro-quinolin-3-ylsulfanyl]-ethyl}-3-methyl-urea. LC/MS m/z 471 (MH)⁺.

EXAMPLE 7

1-{2-[4-(5-Chloro-2-hydroxy-phenyl)-2-oxo-6-trifluoromethyl-1,2-dihydro-quinolin-3-ylsulfanyl]-ethyl}-3-ethyl-urea. LC/MS m/z 485 (MH)⁺.

Intermediate 5

3-tert-Butylsulfanyl-4-(5-chloro-2-methoxyphenyl)-6-trifluoromethyl-1H-quinolin-2-one. Sodium hydride (5.15 g, 60% dispersion in mineral oil, 129 mmol, 3 equiv) was added to a stirred cold (0° C.) solution of 2-methyl-2-propanethiol (11.6 g, 129 mmol, 3 equiv) in THF (200 mL). After 30 min, a solution of 1 (43 mmol) in THF (100 mL) was added and the resultant suspension was stirred overnight. The reaction was refluxed for 1 h, then cooled back to rt prior to quenching with 1N HCl. The product was extracted with EtOAc, dried over MgSO4, and concentrated in vacuo. The crude product was triturated with boiling ether to afford 1 (15.0 g, 82%).

EXAMPLE 8

4-(5-Chloro-2-hydroxyphenyl)-3-mercapto-6-trifluoromethyl-1H-quinolin-2-one. A solution of boron tribromide (1M in DCM, 25 mL, 25 mmol, 1.5 equiv) was added to a stirred cold (−78° C.) solution of 2 (6.9 g, 16 mmol, 1 equiv) in DCM (56 mL). After the addition was complete, the reaction mixture was allowed to warm rt and maintained for an additional 2 h. The reaction was cooled to 0-5° C. and quenched with satd. sodium bicarbonate. The organic layer was separated, washed with water, brine and then dried over magnesium sulfate. The crude product was recrystallized from EtOAc/hexane to provide 3 as a yellow solid: mp>300° C.; 1H NMR (300 MHz, CD₃OD) δ 7.73 (1H, d), 7.51 (1H, d, J=8.7 Hz), 7.23-7.22(m, 2H), 7.17(d, 1H, J=2.7 Hz), 7.02(d, 1H, J=8.7 Hz), 6.74 (m, 1H); MS m/e 370(MH⁺). Anal. Calcd. for C₁₆H₉ClF₃NO₂S: C, 51.69, H, 2.44, N, 3.77. Found: C, 51.91, H, 2.78, N, 3.57.

EXAMPLE 9

4-(5-Chloro-2-methoxyphenyl)-3-mercapto-6-trifluoromethyl-1H-quinolin-2-one. A solution of 2 (1 mmol) in TFA (2-3 mL) containing small amount of anisole was refluxed for 1-2 h. The excess TFA and anisole were removed in vacuo, and the residue was treated with 5% NaHCO3 solution. The product was extracted with EtOAc, dried over magnesium sulfate, and concentrated in vacuo. The crude product was triturated with ether to afford pure titled compound: mp 239-241° C.; 1H NMR (300 MHz, DMSO) δ 7.80 (1H, d, J=7.2 Hz), 7.64-7.56 (2H, d and dd), 7.37(d, 1H, J=2.7 Hz), 7.33 (d, 1H, J=9.90 Hz), 7.03(s, 1H), 3.69 (3H, s); MS m/e 386 (MH+). Anal. Calcd. for C17H11ClF3NO2S.H2O: C, 49.48, H, 3.22, N, 3.47. Found: C, 49.40, H, 2.49, N, 3.21.

General Procedure for the Preparation of Examples 10-20

Sodium hydride (60% dispersion in mineral oil, 3 equiv) was added to a stirred cold (0° C.) solution of 3 (1 equiv) and then followed by addition of appropriate alkylating agent (1.2 equiv). The resultant mixture was allowed to warm to rt and maintained overnight. The reaction was quenched with IN HCl and the product was extracted with EtOAc. Crude product was purified by silica gel chromatography.

EXAMPLE 10

4-(5-Chloro-2-hydroxyphenyl)-3-(2-hydroxyethylsulfanyl)-6-trifluoromethyl-1H-quinolin-2-one. mp 278-279° C.; 1H (300 MHz, CD3OD) 7.77-7.73(dd, J=8.7 Hz and J=1.8 Hz), 7.52 (1H, d, J=8.7 Hz), 7.38-7.34(dd, 1H, J=8.7 Hz and J=2.7 Hz), 7.29(1H, s), 7.11(d, 1H, J=2.7 Hz), 6.99(d, 1H, J=8.7 Hz), 3.58(t, 2H, J=6.9 Hz), 3.15-2.97(m, 2H); MS m/e 415(MH+). Anal. Calcd. for C18H13ClF3NSO3: C, 51.99, H, 3.15, N, 3.29. Found: C, 52.24, H, 3.17, N, 3.29.

EXAMPLE 11

3-[4-(5-Chloro-2-hydroxyphenyl)-2-oxo-6-trifluoromethyl-1,2-dihydro-quinolin-3-ylsulfanyl]. mp 140° C.; ¹H (300 MHz, CD₃OD) δ 7.76(1H, d, J=8.7 Hz), 7.53 (1H, d, J=8.7 Hz), 7.37-7.34(dd, 1H, J=2.7 Hz and J=8.7 Hz), 7.30(s, 1H), 7.11(d, 1H, J=2.7 Hz), 6.98(d, 1H, J=8.7 Hz), 3.25-3.17(m, 2H), 2.67-2.62(m, 2H); MS m/e 424(MH⁺).

EXAMPLE 12

4-(5-Chloro-2-hydroxyphenyl)-3-(2-methoxyethylsulfanyl)-6-trifluoromethyl-1H-quinolin-2-one. mp 230-232° C.; ¹H (300 MHz, CD₃OD) δ 8.32 (1H, s), 7.70(1H, d, J=8.4 Hz), 7.45(1H, d, J=8.4 Hz), 7.10(2H, d, J=8.7 Hz), 6.59(2H, d, J=8.7 Hz),3.64(t, 2H, J=6.0 Hz), 2.91(t, 2H, J=7.5 Hz), 1.82(m, 2H); MS m/e 286(MH⁺). Anal. Calcd. for C₁₃H₁₃F₃N₂O₂: C, 54.55, H, 4.55, N, 9.79. Found: C, 54.06, H, 4.70, N, 9.87.

EXAMPLE 13

4-[4-(5-Chloro-2-hydroxyphenyl)-2-oxo-6-trifluoromethyl-1,2-dihydro-quinolin-3-ylsulfanyl]butyronitrile. mp 217° C.; ¹H (300 MHz, CD₃OD) δ 7.74 (1H, d, J=8.7 Hz), 7.51(1H, d, J=8.7 Hz), 7.39-7.35(1H, m), 7.30(1H, s), 7.09(1H, d, J=2.4 Hz), 6.99(1H, d, J=8.7 Hz), 3.20-3.12(1H, m), 2.96-2.87(m, 1H), 2.38(t, J=7.2 Hz, 2H), 1.80-1.71(m, 2H); MS m/e 438(MH⁺).

EXAMPLE 14

4-(5-Chloro-2-hydroxyphenyl)-3-(3-hydroxypropylsulfanyl)-6-trifluoromethyl-1H-quinolin-2-one. mp 178-180° C.; ¹H NMR (300 MHz, CD₃OD) δ 7.74 (1H, d, J=8.7 Hz), 7.51 (1H, d, J=8.7 Hz), 7.37-7.33(dd, 1H, J=2.7 Hz and 8.7 Hz), 7.30 (s, 1H), 7.08(d, 1H, J=2.7 Hz), 6.96(d, 1H, J=8.7 Hz), 3.49 (2H, t, J=6.0 Hz), 3.03-2.98(dt, 2H), 1.68-1.60(m, 2H); MS m/e 429 (MH⁺). Anal. Calcd. for C₁₉H₁₅ClF₃NO3S: C, 53.09, H, 3.52, N, 3.26. Found: C, 52.34, H, 3.69, N, 2.94.

EXAMPLE 15

4-(5-Chloro-2-methoxyphenyl)-3-(3-hydroxypropylsulfanyl)-6-trifluoromethyl-1H-quinolin-2-one. mp 211° C.; ¹H NMR (300 MHz, DMSO) δ 8.23 (1H, d, J=8.7 Hz), 8.08-7.80 (2H, d and dd), 7.73(d, 1H, J=8.7 Hz), 7.69 (d, 1H, J=2.7 Hz), 7.60(s, 1H ), 4.19 (3H, s), 3.85-3.81(m, 2H), 3.52(m, 2H), 2.03-1.99(m, 2H); MS m/e 443 (MH⁺). Anal. Calcd. for C₂₀H₁₇ClF₃NO₃S: C, 54.12, H, 3.86, N, 3.16. Found: C, 53.44, H, 3.97, N, 2.93.

EXAMPLE 16

4-(5-Chloro-2-methoxyphenyl)-3-(2-hydroxyethylsulfanyl)-6-trifluoromethyl-1H-quinolin-2-one. mp 98-100° C.; ¹H NMR (300 MHz, DMSO) δ 8.13 (1H, d, J=8.6 Hz), 8.01-7.76 (2H, m), 7.71(d, 1H, J=8.6 Hz), 7.63 (d, 1H, J=2.6 Hz), 7.56(s, 1H ), 4.11 (3H, s), 3.95-3.87(m, 2H), 3.12(m, 2H); MS m/e 430 (MH⁺).

EXAMPLE 17

(±)-4-(5-Chloro-2-hydroxyphenyl)-3-(2,3-dihydroxypropylsulfanyl)-6-trifluoromethyl-1H-quinolin-2-one. mp 178-180° C.; ¹H (300 MHz, CDCl₃) δ 7.83-7.79 (1H, dd, J=1.8 Hz and 8.7 Hz), 7.54 (1H, d, J=8.7 Hz), 7.39-7.35(dd, 1H, J=2.7 Hz and 8.7 Hz), 7.22-7.20 (m, 1H), 7.10(s, 1H), 7.02(1H, d, J=8.7 Hz), 4.71(m, 1H), 4.48(m, 1H), 3.45(m, 1H), 3.11-2.91(m, 2H); MS m/e 446 (MH⁺). Anal. Calcd. for C₁₉H₁₅ClF₃NO₄S: C, 51.19, H, 3.39, N, 3.14. Found: C, 52.92, H, 4.59, N, 2.63.

EXAMPLE 18

(S)-4-(5-Chloro-2-hydroxyphenyl)-3-(2,3-dihydroxypropylsulfanyl)-6-trifluoromethyl-1H-quinolin-2-one. ¹H (300 MHz, CDCl₃) δ 7.87 (1H, s), 7.58 (1H, d, J=6.3 Hz), 7.34 (1H, d, J=6.6 Hz), 7.23 (1H, d, J=6.3 Hz), 6.92-6.87 (2H, m), 3.44-3.3.28 (3H, m), 3.09-2.93(2H, m); MS m/e 446 (MH⁺).

EXAMPLE 19

(R)-4-(5-Chloro-2-hydroxyphenyl)-3-(2,3-dihydroxypropylsulfanyl)-6-trifluoromethyl-1H-quinolin-2-one. ¹H (300 MHz, CDCl₃) δ 7.86 (1H, s), 7.59 (1H, d, J=6.3 Hz), 7.33 (1H, d, J=6.6 Hz), 7.25 (1H, d, J=6.3 Hz), 6.94-6.83 (2H, m), 3.41-3.3.26 (3H, m), 3.06-2.90(2H, m); MS m/e 446 (MH⁺).

EXAMPLE 20

4-(5-Chloro-2-methoxyphenyl)-3-(2,3-dihydroxypropylsulfanyl)-6-trifluoromethyl-1H-quinolin-2-one. mp 110-114° C.; ¹H NMR (300 MHz, DMSO) δ 7.82 (1H, d, J=8.7 Hz), 7.58-7.53 (2H, m), 7.32-7.30(m, 1H), 7.25 (d, 1H, J=8.7 Hz), 7.03(s, 1H ), 4.74-4.68 (1H, m), 4.49-4.45(m, 1H), 3.68(s, 3H), 3.41(m, 1H), 3.24-3.20(m, 1H), 2.97-2.89(m, 2H); MS m/e 459 (MH⁺). Anal. Calcd. for C₂₀H₁₇ClF₃NO₄S.0.5H2O: C, 51.19, H, 3.84, N, 2.99. Found: C, 51.97, H, 3.73, N, 2.86.

EXAMPLE 21

4-(5-Chloro-2-methoxy-phenyl)-3-(3-hydroxy-propenylsulfanyl)-6-trifluoromethyl-4a,8a-dihydro-1H-quinolin-2-one. 4-(5-Chloro-2-methoxy-phenyl)-3-oxiranylmethylsulfanyl-6-trifluoromethyl-4a,8a-dihydro-1H-quinolin-2-one (VIII) was prepared by alkylation of 4-(5-Chloro-2-methoxy-phenyl)-3-mercapto-6-trifluoromethyl-4a,8a-dihydro-1H-quinolin-2-one (Ie) with epibromohydrin. To a warm solution of Ie (2.6 mmol) and epibromohydrin (3.9 mmol) in abs. EtOH was added dropwise NaOH solution (1 Molar, 3.9 mL) forming a yellow solution. The alkylation was allowed to proceed at room temperature for an hour. The mixture was evaporated to dryness, redissolved into methylene chloride, washed with water and the organic layer dried over MgSO₄. The desired product was purified by a silica-gel column eluted with mixtures of hexanes and ethyl acetate. The desired product (5) was obtained as an off-white solid in 70% yield, mp 211-212° C. Calcd. for C₂₀H₁₅Cl₁F₃N₁O₃S₁: C, 54.34; H, 3.42; N, 3.17. Found: C, 54.35; H, 3.43, N, 3.01. ¹H NMR (300 MHz, DMSO-d₆) δ 7.94-7.83 (m, 2 H), 7.64 (dt, J=9.0, 2.4 Hz, 1H), 7.39-7.32 (m, 3 H), 5.27-5.21 (m, 1 H), 4.53-4.51 (m, 1 H), 3.99-3.66 (m, 4 H), 3.26-3.24 (m, 1 H), 3.12-3.02 (m, 1H).

4-(5-Chloro-2-methoxy-phenyl)-3-(3-hydroxy-propenylsulfanyl)-6-trifluoromethyl-4a,8a-dihydro-1H-quinolin-2-one (Ig) was prepared by a base-mediated epoxide rearrangement process. To a solution of VIII (0.2 g, 0.45 mmol) in dry THF (4 mL) at −78° C. under nitrogen was added a THF solution of lithium diisopropylamide (LDA, used as supplied by Aldrich, 1.5 Molar, 0.6 mL). The mixture was stirred at −78° C. for a further 10 min. before it was allowed to warm to room temperature and stirring was continued for another 30 min. It was quenched with saturated solution of NH₄Cl, organic residues were extracted into ethyl acetate. The organic layers were combined and dried over MgSO₄. Evaporation of solvent gave 0.18 g (90% yield) of the desired product as pale yellow solid, mp 148-150° C. Calcd. for C₂₀H₁₅Cl₁F₃N₁O₃S₁: C, 54.34; H, 3.42; N, 3.17; F, 12.90; Cl, 8.02. Found: C, 54.34; H, 3.66, N, 2.93; F, 12.80; Cl, 7.95. ¹H NMR (300 MHz, DMSO-d₆) δ 12.51 (s, 1H), 7.84 (d, J=10.2 Hz, 1 H), 7.58-7.54 (m, 2 H), 7.30-7.23 (m, 2 H), 7.08 (s, 1 H), 6.28 (d, J=15.3 Hz, 1 H), 5.58 (dt, J=15.3, 5.4 Hz, 1H), 4.74 (t, J=5.7 Hz, 1 H), 3.84 (t, J=6.0 Hz, 2 H), 3.69 (s, 3H). 

1. A compound of formula (I)

wherein: R and R¹ are independently hydrogen or methyl; R², R³, and R⁴ are independently hydrogen, halogen, cyano, nitro, or trifluoromethyl, provided R², R³, and R⁴ are not all hydrogen; R⁵ is bromo, chloro, or nitro; B is —CH₂—, —CH₂CH₂—, —CH═CHCH₂—, —CH₂CH₂CH₂—, or —CH₂CH(OH)CH₂—; D is OR⁶, CN, N(R⁶)₂, NHC(═O)NHR⁶, or CO₂R⁶; or B-D taken together is hydrogen; R⁶ is hydrogen or C₁₋₄ alkyl; or a pharmaceutically acceptable salt or solvate thereof.
 2. A compound of claim 2 where R is hydrogen.
 3. A compound of claim 2 where R¹ is hydrogen.
 4. A compound of claim 1 where R² is hydrogen, R³ is trifluoromethyl, and R⁴ is hydrogen.
 5. A compound of claim 2 where R⁵ is chloro.
 6. A compound of claim 2 where B-D is hydrogen.
 7. A compound of claim 1 selected from the group consisting of [4-(5-Chloro-2-hydroxy-phenyl)-2-oxo-6-trifluoromethyl- 1,2-dihydro-quinolin-3-ylsulfanyl]-acetic acid; 1-{2-[4-(5-Chloro-2-methoxy-phenyl)-2-oxo-6-trifluoromethyl-1,2-dihydro-quinolin-3-ylsulfanyl]-ethyl}-3-methyl-urea; 1-{2-[4-(5-Chloro-2-methoxy-phenyl)-2-oxo-6-trifluoromethyl- 1,2-dihydro-quinolin-3-ylsulfanyl]-ethyl}-3-ethyl-urea; 1-{2- [4-(5-Chloro-2-methoxy-phenyl)-2-oxo-6-trifluoromethyl- 1,2-dihydro-quinolin-3-ylsulfanyl]-ethyl }urea; 1-{2-[4-(5-Chloro-2-hydroxy-phenyl)-2-oxo-6-trifluoromethyl- 1,2-dihydro-quinolin-3-ylsulfanyl]-ethyl}urea; 1-{2-[4-(5-Chloro-2-hydroxy-phenyl)-2-oxo-6-trifluoromethyl-1,2-dihydro-quinolin-3-ylsulfanyl]-ethyl }-3-methyl-urea; 1-{2-[4-(5-Chloro-2-hydroxy-phenyl)-2-oxo-6-trifluoromethyl-1,2-dihydro-quinolin-3-ylsulfanyl]-ethyl }-3-ethyl-urea; 4-(5-Chloro-2-hydroxyphenyl)-3-mercapto-6-trifluoromethyl- 1 H-quinolin-2-one; 4-(5-Chloro-2-methoxyphenyl)-3-mercapto-6-trifluoromethyl- 1H-quinolin-2-one; 4-(5-Chloro-2-hydroxyphenyl)-3-(2-hydroxyethylsulfanyl)-6-trifluoromethyl- 1H-quinolin-2-one; 3-[4-(5-Chloro-2-hydroxyphenyl)-2-oxo-6-trifluoromethyl- 1,2-dihydro-quinolin-3-ylsulfanyl]propionitrile; 4-(5-Chloro-2-hydroxyphenyl)-3-(2-methoxyethylsulfanyl)-6-trifluoromethyl-1H-quinolin-2-one; 4-[4-(5-Chloro-2-hydroxyphenyl)-2-oxo-6-trifluoromethyl-1,2-dihydro-quinolin-3-ylsulfanyl]butyronitrile; 4-(5-Chloro-2-hydroxyphenyl)-3-(3-hydroxypropylsulfanyl)-6-trifluoromethyl-1H-quinolin-2-one; 4-(5-Chloro-2-methoxyphenyl)-3-(3-hydroxypropylsulfanyl)-6-trifluoromethyl-1H-quinolin-2-one; 4-(5-Chloro-2-methoxyphenyl)-3-(2-hydroxyethylsulfanyl)-6-trifluoromethyl-1H-quinolin-2-one; (±)-4-(5-Chloro-2-hydroxyphenyl)-3-(2,3-dihydroxypropylsulfanyl)-6-trifluoromethyl- 1 H-quinolin-2-one; (S)-4-(5-Chloro-2-hydroxyphenyl)-3-(2,3-dihydroxypropylsulfanyl)-6-trifluoromethyl- 1 H-quinolin-2-one; (R)-4-(5-Chloro-2-hydroxyphenyl)-3-(2,3-dihydroxypropylsulfanyl)-6-trifluoromethyl- 1 H-quinolin-2-one; 4-(5-Chloro-2-methoxyphenyl)-3-(2,3-dihydroxypropylsulfanyl)-6-trifluoromethyl-1H-quinolin-2-one; 4-(5-Chloro-2-methoxy-phenyl)-3-(3-hydroxy-propenylsulfanyl)-6-trifluoromethyl-4a,8a-dihydro-1H-quinolin-2-one; and salts and solvates thereof.
 8. A pharmaceutical composition comprising a therapeutically effective amount of a compound of claim 1 and a pharmaceutically acceptable carrier.
 9. A method of modulating potassium channels comprising administering a therapeutically effective amount of a compound of claim 1 to a patient suffering from a condition which can be treated by the modulation of potassium channels.
 10. The method of claim 9 where the condition is erectile dysfunction.
 11. The method of claim 9 where the condition is irritable bowel syndrome. 